Verifying Googlebot and other Google crawlers

You can verify if a web crawler accessing your server really is a Google crawler, such as Googlebot. This is useful if you're concerned that spammers or other troublemakers are accessing your site while claiming to be Googlebot.

There are two methods for verifying Google's crawlers:

  • Manually: For one-off lookups, use command line tools. This method is sufficient for most use cases.
  • Automatically: For large scale lookups, use an automatic solution to match a crawler's IP address against the list of published Googlebot IP addresses.

Use command line tools

  1. Run a reverse DNS lookup on the accessing IP address from your logs, using the host command.
  2. Verify that the domain name is either googlebot.com or google.com.
  3. Run a forward DNS lookup on the domain name retrieved in step 1 using the host command on the retrieved domain name.
  4. Verify that it's the same as the original accessing IP address from your logs.

Example 1:

host 66.249.66.1
1.66.249.66.in-addr.arpa domain name pointer crawl-66-249-66-1.googlebot.com.

host crawl-66-249-66-1.googlebot.com
crawl-66-249-66-1.googlebot.com has address 66.249.66.1

Example 2:

host 66.249.90.77
77.90.249.66.in-addr.arpa domain name pointer rate-limited-proxy-66-249-90-77.google.com.

host rate-limited-proxy-66-249-90-77.google.com
rate-limited-proxy-66-249-90-77.google.com has address 66.249.90.77

Use automatic solutions

Alternatively, you can identify Googlebot by IP address by matching the crawler's IP address to the list of Googlebot IP addresses. For all other Google crawlers, match the crawler's IP address against the complete list of Google IP addresses.